Many devices, such as organic light emitting devices and the like, are susceptible to degradation from the permeation of certain liquids and gases, such as water vapor and oxygen present in the environment, and other chemicals that may be used during the manufacture, handling or storage of the product. To reduce permeability to these damaging liquids, gases and chemicals, the devices are typically encapsulated with a multilayer barrier stack adjacent one or both sides of the device.
In general, a barrier stack includes multiple dyads, each dyad being a two-layered structure including a barrier layer and a decoupling layer. The barrier stack can be deposited directly on the device to be protected, or may be deposited on a separate film or support, and then laminated onto the device. Because the device to be encapsulated by the barrier stack is sensitive to water vapor and oxygen, deposition of the barrier stack (whether by direct encapsulation or lamination) is conducted in an inert environment so as not to expose the device to the damaging gasses during the deposition process (and before the protective stack has been deposited). In particular, these sensitive devices are typically encapsulated by entering them into a deposition machine having multiple chambers, all of which are maintained in an inert condition (i.e., devoid of reactive gasses and species, such as, e.g., water vapor and oxygen). However, as noted above, barrier stacks typically include multiple dyads, which increases the size of the machine needed to deposit the stack. Specifically, as shown in FIG. 4, a conventional deposition machine for depositing a barrier stack having three dyads has six (or seven if a protective layer is deposited) separate deposition chambers, all of which must be maintained under inert conditions. The numerous deposition chambers needed for deposition of each layer under inert conditions increases the size and cost of the machine, leading to increased manufacturing costs not only in the costs associated with maintaining inert conditions in multiple chambers, but also in the costs associated with housing and maintaining such a large machine.